A grey rock, said Ruskin, is a good sitter. That is one type of behavior. A darting dragon-fly is another type of behavior. We call the one alive, the other not. But both are fundamentally balances of give and take of motion with their surround. To make "life" a distinction between them is at root to treat them both artificially.
Man on His Nature, Chapter III (p. 88), Doubleday Anchor Books. 1955